--- /dev/null
+1.5.0
+=====
+
+### Significant changes relative to 1.5 beta1:
+
+1. Fixed an issue whereby a malformed motion-JPEG frame could cause the "fast
+path" of libjpeg-turbo's Huffman decoder to read from uninitialized memory.
+
++2. Added libjpeg-turbo version and build information to the global string table
++of the libjpeg and TurboJPEG API libraries. This is a common practice in other
++infrastructure libraries, such as OpenSSL and libpng, because it makes it easy
++to examine an application binary and determine which version of the library the
++application was linked against.
++
+
+1.4.90 (1.5 beta1)
+==================
+
+### Significant changes relative to 1.4.2:
+
+1. Added full SIMD acceleration for PowerPC platforms using AltiVec VMX
+(128-bit SIMD) instructions. Although the performance of libjpeg-turbo on
+PowerPC was already good, due to the increased number of registers available
+to the compiler vs. x86, it was still possible to speed up compression by about
+3-4x and decompression by about 2-2.5x (relative to libjpeg v6b) through the
+use of AltiVec instructions.
+
+2. Added two new libjpeg API functions (`jpeg_skip_scanlines()` and
+`jpeg_crop_scanline()`) that can be used to partially decode a JPEG image. See
+[libjpeg.txt](libjpeg.txt) for more details.
+
+3. The TJCompressor and TJDecompressor classes in the TurboJPEG Java API now
+implement the Closeable interface, so those classes can be used with a
+try-with-resources statement.
+
+4. The TurboJPEG Java classes now throw unchecked idiomatic exceptions
+(IllegalArgumentException, IllegalStateException) for unrecoverable errors
+caused by incorrect API usage, and those classes throw a new checked exception
+type (TJException) for errors that are passed through from the C library.
+
+5. Source buffers for the TurboJPEG C API functions, as well as the
+`jpeg_mem_src()` function in the libjpeg API, are now declared as const
+pointers. This facilitates passing read-only buffers to those functions and
+ensures the caller that the source buffer will not be modified. This should
+not create any backward API or ABI incompatibilities with prior libjpeg-turbo
+releases.
+
+6. The MIPS DSPr2 SIMD code can now be compiled to support either FR=0 or FR=1
+FPUs.
+
+7. Fixed additional negative left shifts and other issues reported by the GCC
+and Clang undefined behavior sanitizers. Most of these issues affected only
+32-bit code, and none of them was known to pose a security threat, but removing
+the warnings makes it easier to detect actual security issues, should they
+arise in the future.
+
+8. Removed the unnecessary `.arch` directive from the ARM64 NEON SIMD code.
+This directive was preventing the code from assembling using the clang
+integrated assembler.
+
+9. Fixed a regression caused by 1.4.1[6] that prevented 32-bit and 64-bit
+libjpeg-turbo RPMs from being installed simultaneously on recent Red Hat/Fedora
+distributions. This was due to the addition of a macro in jconfig.h that
+allows the Huffman codec to determine the word size at compile time. Since
+that macro differs between 32-bit and 64-bit builds, this caused a conflict
+between the i386 and x86_64 RPMs (any differing files, other than executables,
+are not allowed when 32-bit and 64-bit RPMs are installed simultaneously.)
+Since the macro is used only internally, it has been moved into jconfigint.h.
+
+10. The x86-64 SIMD code can now be disabled at run time by setting the
+`JSIMD_FORCENONE` environment variable to `1` (the other SIMD implementations
+already had this capability.)
+
+11. Added a new command-line argument to TJBench (`-nowrite`) that prevents the
+benchmark from outputting any images. This removes any potential operating
+system overhead that might be caused by lazy writes to disk and thus improves
+the consistency of the performance measurements.
+
+12. Added SIMD acceleration for Huffman encoding on SSE2-capable x86 and x86-64
+platforms. This speeds up the compression of full-color JPEGs by about 10-15%
+on average (relative to libjpeg-turbo 1.4.x) when using modern Intel and AMD
+CPUs. Additionally, this works around an issue in the clang optimizer that
+prevents it (as of this writing) from achieving the same performance as GCC
+when compiling the C version of the Huffman encoder
+(<https://llvm.org/bugs/show_bug.cgi?id=16035>). For the purposes of
+benchmarking or regression testing, SIMD-accelerated Huffman encoding can be
+disabled by setting the `JSIMD_NOHUFFENC` environment variable to `1`.
+
+13. Added ARM 64-bit (ARMv8) NEON SIMD implementations of the commonly-used
+compression algorithms (including the slow integer forward DCT and h2v2 & h2v1
+downsampling algorithms, which are not accelerated in the 32-bit NEON
+implementation.) This speeds up the compression of full-color JPEGs by about
+75% on average on a Cavium ThunderX processor and by about 2-2.5x on average on
+Cortex-A53 and Cortex-A57 cores.
+
+14. Added SIMD acceleration for Huffman encoding on NEON-capable ARM 32-bit
+and 64-bit platforms.
+
+ For 32-bit code, this speeds up the compression of full-color JPEGs by
+about 30% on average on a typical iOS device (iPhone 4S, Cortex-A9) and by
+about 6-7% on average on a typical Android device (Nexus 5X, Cortex-A53 and
+Cortex-A57), relative to libjpeg-turbo 1.4.x. Note that the larger speedup
+under iOS is due to the fact that iOS builds use LLVM, which does not optimize
+the C Huffman encoder as well as GCC does.
+
+ For 64-bit code, NEON-accelerated Huffman encoding speeds up the
+compression of full-color JPEGs by about 40% on average on a typical iOS device
+(iPhone 5S, Apple A7) and by about 7-8% on average on a typical Android device
+(Nexus 5X, Cortex-A53 and Cortex-A57), in addition to the speedup described in
+[13] above.
+
+ For the purposes of benchmarking or regression testing, SIMD-accelerated
+Huffman encoding can be disabled by setting the `JSIMD_NOHUFFENC` environment
+variable to `1`.
+
+15. pkg-config (.pc) scripts are now included for both the libjpeg and
+TurboJPEG API libraries on Un*x systems. Note that if a project's build system
+relies on these scripts, then it will not be possible to build that project
+with libjpeg or with a prior version of libjpeg-turbo.
+
+16. Optimized the ARM 64-bit (ARMv8) NEON SIMD decompression routines to
+improve performance on CPUs with in-order pipelines. This speeds up the
+decompression of full-color JPEGs by nearly 2x on average on a Cavium ThunderX
+processor and by about 15% on average on a Cortex-A53 core.
+
+17. Fixed an issue in the accelerated Huffman decoder that could have caused
+the decoder to read past the end of the input buffer when a malformed,
+specially-crafted JPEG image was being decompressed. In prior versions of
+libjpeg-turbo, the accelerated Huffman decoder was invoked (in most cases) only
+if there were > 128 bytes of data in the input buffer. However, it is possible
+to construct a JPEG image in which a single Huffman block is over 430 bytes
+long, so this version of libjpeg-turbo activates the accelerated Huffman
+decoder only if there are > 512 bytes of data in the input buffer.
+
+18. Fixed a memory leak in tjunittest encountered when running the program
+with the `-yuv` option.
+
+
+1.4.2
+=====
+
+### Significant changes relative to 1.4.1:
+
+1. Fixed an issue whereby cjpeg would segfault if a Windows bitmap with a
+negative width or height was used as an input image (Windows bitmaps can have
+a negative height if they are stored in top-down order, but such files are
+rare and not supported by libjpeg-turbo.)
+
+2. Fixed an issue whereby, under certain circumstances, libjpeg-turbo would
+incorrectly encode certain JPEG images when quality=100 and the fast integer
+forward DCT were used. This was known to cause `make test` to fail when the
+library was built with `-march=haswell` on x86 systems.
+
+3. Fixed an issue whereby libjpeg-turbo would crash when built with the latest
+& greatest development version of the Clang/LLVM compiler. This was caused by
+an x86-64 ABI conformance issue in some of libjpeg-turbo's 64-bit SSE2 SIMD
+routines. Those routines were incorrectly using a 64-bit `mov` instruction to
+transfer a 32-bit JDIMENSION argument, whereas the x86-64 ABI allows the upper
+(unused) 32 bits of a 32-bit argument's register to be undefined. The new
+Clang/LLVM optimizer uses load combining to transfer multiple adjacent 32-bit
+structure members into a single 64-bit register, and this exposed the ABI
+conformance issue.
+
+4. Fixed a bug in the MIPS DSPr2 4:2:0 "plain" (non-fancy and non-merged)
+upsampling routine that caused a buffer overflow (and subsequent segfault) when
+decompressing a 4:2:0 JPEG image whose scaled output width was less than 16
+pixels. The "plain" upsampling routines are normally only used when
+decompressing a non-YCbCr JPEG image, but they are also used when decompressing
+a JPEG image whose scaled output height is 1.
+
+5. Fixed various negative left shifts and other issues reported by the GCC and
+Clang undefined behavior sanitizers. None of these was known to pose a
+security threat, but removing the warnings makes it easier to detect actual
+security issues, should they arise in the future.
+
+
+1.4.1
+=====
+
+### Significant changes relative to 1.4.0:
+
+1. tjbench now properly handles CMYK/YCCK JPEG files. Passing an argument of
+`-cmyk` (instead of, for instance, `-rgb`) will cause tjbench to internally
+convert the source bitmap to CMYK prior to compression, to generate YCCK JPEG
+files, and to internally convert the decompressed CMYK pixels back to RGB after
+decompression (the latter is done automatically if a CMYK or YCCK JPEG is
+passed to tjbench as a source image.) The CMYK<->RGB conversion operation is
+not benchmarked. NOTE: The quick & dirty CMYK<->RGB conversions that tjbench
+uses are suitable for testing only. Proper conversion between CMYK and RGB
+requires a color management system.
+
+2. `make test` now performs additional bitwise regression tests using tjbench,
+mainly for the purpose of testing compression from/decompression to a subregion
+of a larger image buffer.
+
+3. `make test` no longer tests the regression of the floating point DCT/IDCT
+by default, since the results of those tests can vary if the algorithms in
+question are not implemented using SIMD instructions on a particular platform.
+See the comments in [Makefile.am](Makefile.am) for information on how to
+re-enable the tests and to specify an expected result for them based on the
+particulars of your platform.
+
+4. The NULL color conversion routines have been significantly optimized,
+which speeds up the compression of RGB and CMYK JPEGs by 5-20% when using
+64-bit code and 0-3% when using 32-bit code, and the decompression of those
+images by 10-30% when using 64-bit code and 3-12% when using 32-bit code.
+
+5. Fixed an "illegal instruction" error that occurred when djpeg from a
+SIMD-enabled libjpeg-turbo MIPS build was executed with the `-nosmooth` option
+on a MIPS machine that lacked DSPr2 support. The MIPS SIMD routines for h2v1
+and h2v2 merged upsampling were not properly checking for the existence of
+DSPr2.
+
+6. Performance has been improved significantly on 64-bit non-Linux and
+non-Windows platforms (generally 10-20% faster compression and 5-10% faster
+decompression.) Due to an oversight, the 64-bit version of the accelerated
+Huffman codec was not being compiled in when libjpeg-turbo was built on
+platforms other than Windows or Linux. Oops.
+
+7. Fixed an extremely rare bug in the Huffman encoder that caused 64-bit
+builds of libjpeg-turbo to incorrectly encode a few specific test images when
+quality=98, an optimized Huffman table, and the slow integer forward DCT were
+used.
+
+8. The Windows (CMake) build system now supports building only static or only
+shared libraries. This is accomplished by adding either `-DENABLE_STATIC=0` or
+`-DENABLE_SHARED=0` to the CMake command line.
+
+9. TurboJPEG API functions will now return an error code if a warning is
+triggered in the underlying libjpeg API. For instance, if a JPEG file is
+corrupt, the TurboJPEG decompression functions will attempt to decompress
+as much of the image as possible, but those functions will now return -1 to
+indicate that the decompression was not entirely successful.
+
+10. Fixed a bug in the MIPS DSPr2 4:2:2 fancy upsampling routine that caused a
+buffer overflow (and subsequent segfault) when decompressing a 4:2:2 JPEG image
+in which the right-most MCU was 5 or 6 pixels wide.
+
+
+1.4.0
+=====
+
+### Significant changes relative to 1.4 beta1:
+
+1. Fixed a build issue on OS X PowerPC platforms (md5cmp failed to build
+because OS X does not provide the `le32toh()` and `htole32()` functions.)
+
+2. The non-SIMD RGB565 color conversion code did not work correctly on big
+endian machines. This has been fixed.
+
+3. Fixed an issue in `tjPlaneSizeYUV()` whereby it would erroneously return 1
+instead of -1 if `componentID` was > 0 and `subsamp` was `TJSAMP_GRAY`.
+
+3. Fixed an issue in `tjBufSizeYUV2()` whereby it would erroneously return 0
+instead of -1 if `width` was < 1.
+
+5. The Huffman encoder now uses `clz` and `bsr` instructions for bit counting
+on ARM64 platforms (see 1.4 beta1[5].)
+
+6. The `close()` method in the TJCompressor and TJDecompressor Java classes is
+now idempotent. Previously, that method would call the native `tjDestroy()`
+function even if the TurboJPEG instance had already been destroyed. This
+caused an exception to be thrown during finalization, if the `close()` method
+had already been called. The exception was caught, but it was still an
+expensive operation.
+
+7. The TurboJPEG API previously generated an error (`Could not determine
+subsampling type for JPEG image`) when attempting to decompress grayscale JPEG
+images that were compressed with a sampling factor other than 1 (for instance,
+with `cjpeg -grayscale -sample 2x2`). Subsampling technically has no meaning
+with grayscale JPEGs, and thus the horizontal and vertical sampling factors
+for such images are ignored by the decompressor. However, the TurboJPEG API
+was being too rigid and was expecting the sampling factors to be equal to 1
+before it treated the image as a grayscale JPEG.
+
+8. cjpeg, djpeg, and jpegtran now accept an argument of `-version`, which will
+print the library version and exit.
+
+9. Referring to 1.4 beta1[15], another extremely rare circumstance was
+discovered under which the Huffman encoder's local buffer can be overrun
+when a buffered destination manager is being used and an
+extremely-high-frequency block (basically junk image data) is being encoded.
+Even though the Huffman local buffer was increased from 128 bytes to 136 bytes
+to address the previous issue, the new issue caused even the larger buffer to
+be overrun. Further analysis reveals that, in the absolute worst case (such as
+setting alternating AC coefficients to 32767 and -32768 in the JPEG scanning
+order), the Huffman encoder can produce encoded blocks that approach double the
+size of the unencoded blocks. Thus, the Huffman local buffer was increased to
+256 bytes, which should prevent any such issue from re-occurring in the future.
+
+10. The new `tjPlaneSizeYUV()`, `tjPlaneWidth()`, and `tjPlaneHeight()`
+functions were not actually usable on any platform except OS X and Windows,
+because those functions were not included in the libturbojpeg mapfile. This
+has been fixed.
+
+11. Restored the `JPP()`, `JMETHOD()`, and `FAR` macros in the libjpeg-turbo
+header files. The `JPP()` and `JMETHOD()` macros were originally implemented
+in libjpeg as a way of supporting non-ANSI compilers that lacked support for
+prototype parameters. libjpeg-turbo has never supported such compilers, but
+some software packages still use the macros to define their own prototypes.
+Similarly, libjpeg-turbo has never supported MS-DOS and other platforms that
+have far symbols, but some software packages still use the `FAR` macro. A
+pretty good argument can be made that this is a bad practice on the part of the
+software in question, but since this affects more than one package, it's just
+easier to fix it here.
+
+12. Fixed issues that were preventing the ARM 64-bit SIMD code from compiling
+for iOS, and included an ARMv8 architecture in all of the binaries installed by
+the "official" libjpeg-turbo SDK for OS X.
+
+
+1.3.90 (1.4 beta1)
+==================
+
+### Significant changes relative to 1.3.1:
+
+1. New features in the TurboJPEG API:
+
+ - YUV planar images can now be generated with an arbitrary line padding
+(previously only 4-byte padding, which was compatible with X Video, was
+supported.)
+ - The decompress-to-YUV function has been extended to support image
+scaling.
+ - JPEG images can now be compressed from YUV planar source images.
+ - YUV planar images can now be decoded into RGB or grayscale images.
+ - 4:1:1 subsampling is now supported. This is mainly included for
+compatibility, since 4:1:1 is not fully accelerated in libjpeg-turbo and has no
+significant advantages relative to 4:2:0.
+ - CMYK images are now supported. This feature allows CMYK source images
+to be compressed to YCCK JPEGs and YCCK or CMYK JPEGs to be decompressed to
+CMYK destination images. Conversion between CMYK/YCCK and RGB or YUV images is
+not supported. Such conversion requires a color management system and is thus
+out of scope for a codec library.
+ - The handling of YUV images in the Java API has been significantly
+refactored and should now be much more intuitive.
+ - The Java API now supports encoding a YUV image from an arbitrary
+position in a large image buffer.
+ - All of the YUV functions now have a corresponding function that operates
+on separate image planes instead of a unified image buffer. This allows for
+compressing/decoding from or decompressing/encoding to a subregion of a larger
+YUV image. It also allows for handling YUV formats that swap the order of the
+U and V planes.
+
+2. Added SIMD acceleration for DSPr2-capable MIPS platforms. This speeds up
+the compression of full-color JPEGs by 70-80% on such platforms and
+decompression by 25-35%.
+
+3. If an application attempts to decompress a Huffman-coded JPEG image whose
+header does not contain Huffman tables, libjpeg-turbo will now insert the
+default Huffman tables. In order to save space, many motion JPEG video frames
+are encoded without the default Huffman tables, so these frames can now be
+successfully decompressed by libjpeg-turbo without additional work on the part
+of the application. An application can still override the Huffman tables, for
+instance to re-use tables from a previous frame of the same video.
+
+4. The Mac packaging system now uses pkgbuild and productbuild rather than
+PackageMaker (which is obsolete and no longer supported.) This means that
+OS X 10.6 "Snow Leopard" or later must be used when packaging libjpeg-turbo,
+although the packages produced can be installed on OS X 10.5 "Leopard" or
+later. OS X 10.4 "Tiger" is no longer supported.
+
+5. The Huffman encoder now uses `clz` and `bsr` instructions for bit counting
+on ARM platforms rather than a lookup table. This reduces the memory footprint
+by 64k, which may be important for some mobile applications. Out of four
+Android devices that were tested, two demonstrated a small overall performance
+loss (~3-4% on average) with ARMv6 code and a small gain (also ~3-4%) with
+ARMv7 code when enabling this new feature, but the other two devices
+demonstrated a significant overall performance gain with both ARMv6 and ARMv7
+code (~10-20%) when enabling the feature. Actual mileage may vary.
+
+6. Worked around an issue with Visual C++ 2010 and later that caused incorrect
+pixels to be generated when decompressing a JPEG image to a 256-color bitmap,
+if compiler optimization was enabled when libjpeg-turbo was built. This caused
+the regression tests to fail when doing a release build under Visual C++ 2010
+and later.
+
+7. Improved the accuracy and performance of the non-SIMD implementation of the
+floating point inverse DCT (using code borrowed from libjpeg v8a and later.)
+The accuracy of this implementation now matches the accuracy of the SSE/SSE2
+implementation. Note, however, that the floating point DCT/IDCT algorithms are
+mainly a legacy feature. They generally do not produce significantly better
+accuracy than the slow integer DCT/IDCT algorithms, and they are quite a bit
+slower.
+
+8. Added a new output colorspace (`JCS_RGB565`) to the libjpeg API that allows
+for decompressing JPEG images into RGB565 (16-bit) pixels. If dithering is not
+used, then this code path is SIMD-accelerated on ARM platforms.
+
+9. Numerous obsolete features, such as support for non-ANSI compilers and
+support for the MS-DOS memory model, were removed from the libjpeg code,
+greatly improving its readability and making it easier to maintain and extend.
+
+10. Fixed a segfault that occurred when calling `output_message()` with
+`msg_code` set to `JMSG_COPYRIGHT`.
+
+11. Fixed an issue whereby wrjpgcom was allowing comments longer than 65k
+characters to be passed on the command line, which was causing it to generate
+incorrect JPEG files.
+
+12. Fixed a bug in the build system that was causing the Windows version of
+wrjpgcom to be built using the rdjpgcom source code.
+
+13. Restored 12-bit-per-component JPEG support. A 12-bit version of
+libjpeg-turbo can now be built by passing an argument of `--with-12bit` to
+configure (Unix) or `-DWITH_12BIT=1` to cmake (Windows.) 12-bit JPEG support
+is included only for convenience. Enabling this feature disables all of the
+performance features in libjpeg-turbo, as well as arithmetic coding and the
+TurboJPEG API. The resulting library still contains the other libjpeg-turbo
+features (such as the colorspace extensions), but in general, it performs no
+faster than libjpeg v6b.
+
+14. Added ARM 64-bit SIMD acceleration for the YCC-to-RGB color conversion
+and IDCT algorithms (both are used during JPEG decompression.) For unknown
+reasons (probably related to clang), this code cannot currently be compiled for
+iOS.
+
+15. Fixed an extremely rare bug that could cause the Huffman encoder's local
+buffer to overrun when a very high-frequency MCU is compressed using quality
+100 and no subsampling, and when the JPEG output buffer is being dynamically
+resized by the destination manager. This issue was so rare that, even with a
+test program specifically designed to make the bug occur (by injecting random
+high-frequency YUV data into the compressor), it was reproducible only once in
+about every 25 million iterations.
+
+16. Fixed an oversight in the TurboJPEG C wrapper: if any of the JPEG
+compression functions was called repeatedly with the same
+automatically-allocated destination buffer, then TurboJPEG would erroneously
+assume that the `jpegSize` parameter was equal to the size of the buffer, when
+in fact that parameter was probably equal to the size of the most recently
+compressed JPEG image. If the size of the previous JPEG image was not as large
+as the current JPEG image, then TurboJPEG would unnecessarily reallocate the
+destination buffer.
+
+
+1.3.1
+=====
+
+### Significant changes relative to 1.3.0:
+
+1. On Un*x systems, `make install` now installs the libjpeg-turbo libraries
+into /opt/libjpeg-turbo/lib32 by default on any 32-bit system, not just x86,
+and into /opt/libjpeg-turbo/lib64 by default on any 64-bit system, not just
+x86-64. You can override this by overriding either the `prefix` or `libdir`
+configure variables.
+
+2. The Windows installer now places a copy of the TurboJPEG DLLs in the same
+directory as the rest of the libjpeg-turbo binaries. This was mainly done
+to support TurboVNC 1.3, which bundles the DLLs in its Windows installation.
+When using a 32-bit version of CMake on 64-bit Windows, it is impossible to
+access the c:\WINDOWS\system32 directory, which made it impossible for the
+TurboVNC build scripts to bundle the 64-bit TurboJPEG DLL.
+
+3. Fixed a bug whereby attempting to encode a progressive JPEG with arithmetic
+entropy coding (by passing arguments of `-progressive -arithmetic` to cjpeg or
+jpegtran, for instance) would result in an error, `Requested feature was
+omitted at compile time`.
+
+4. Fixed a couple of issues whereby malformed JPEG images would cause
+libjpeg-turbo to use uninitialized memory during decompression.
+
+5. Fixed an error (`Buffer passed to JPEG library is too small`) that occurred
+when calling the TurboJPEG YUV encoding function with a very small (< 5x5)
+source image, and added a unit test to check for this error.
+
+6. The Java classes should now build properly under Visual Studio 2010 and
+later.
+
+7. Fixed an issue that prevented SRPMs generated using the in-tree packaging
+tools from being rebuilt on certain newer Linux distributions.
+
+8. Numerous minor fixes to eliminate compilation and build/packaging system
+warnings, fix cosmetic issues, improve documentation clarity, and other general
+source cleanup.
+
+
+1.3.0
+=====
+
+### Significant changes relative to 1.3 beta1:
+
+1. `make test` now works properly on FreeBSD, and it no longer requires the
+md5sum executable to be present on other Un*x platforms.
+
+2. Overhauled the packaging system:
+
+ - To avoid conflict with vendor-supplied libjpeg-turbo packages, the
+official RPMs and DEBs for libjpeg-turbo have been renamed to
+"libjpeg-turbo-official".
+ - The TurboJPEG libraries are now located under /opt/libjpeg-turbo in the
+official Linux and Mac packages, to avoid conflict with vendor-supplied
+packages and also to streamline the packaging system.
+ - Release packages are now created with the directory structure defined
+by the configure variables `prefix`, `bindir`, `libdir`, etc. (Un\*x) or by the
+`CMAKE_INSTALL_PREFIX` variable (Windows.) The exception is that the docs are
+always located under the system default documentation directory on Un\*x and
+Mac systems, and on Windows, the TurboJPEG DLL is always located in the Windows
+system directory.
+ - To avoid confusion, official libjpeg-turbo packages on Linux/Unix
+platforms (except for Mac) will always install the 32-bit libraries in
+/opt/libjpeg-turbo/lib32 and the 64-bit libraries in /opt/libjpeg-turbo/lib64.
+ - Fixed an issue whereby, in some cases, the libjpeg-turbo executables on
+Un*x systems were not properly linking with the shared libraries installed by
+the same package.
+ - Fixed an issue whereby building the "installer" target on Windows when
+`WITH_JAVA=1` would fail if the TurboJPEG JAR had not been previously built.
+ - Building the "install" target on Windows now installs files into the
+same places that the installer does.
+
+3. Fixed a Huffman encoder bug that prevented I/O suspension from working
+properly.
+
+
+1.2.90 (1.3 beta1)
+==================
+
+### Significant changes relative to 1.2.1:
+
+1. Added support for additional scaling factors (3/8, 5/8, 3/4, 7/8, 9/8, 5/4,
+11/8, 3/2, 13/8, 7/4, 15/8, and 2) when decompressing. Note that the IDCT will
+not be SIMD-accelerated when using any of these new scaling factors.
+
+2. The TurboJPEG dynamic library is now versioned. It was not strictly
+necessary to do so, because TurboJPEG uses versioned symbols, and if a function
+changes in an ABI-incompatible way, that function is renamed and a legacy
+function is provided to maintain backward compatibility. However, certain
+Linux distro maintainers have a policy against accepting any library that isn't
+versioned.
+
+3. Extended the TurboJPEG Java API so that it can be used to compress a JPEG
+image from and decompress a JPEG image to an arbitrary position in a large
+image buffer.
+
+4. The `tjDecompressToYUV()` function now supports the `TJFLAG_FASTDCT` flag.
+
+5. The 32-bit supplementary package for amd64 Debian systems now provides
+symlinks in /usr/lib/i386-linux-gnu for the TurboJPEG libraries in /usr/lib32.
+This allows those libraries to be used on MultiArch-compatible systems (such as
+Ubuntu 11 and later) without setting the linker path.
+
+6. The TurboJPEG Java wrapper should now find the JNI library on Mac systems
+without having to pass `-Djava.library.path=/usr/lib` to java.
+
+7. TJBench has been ported to Java to provide a convenient way of validating
+the performance of the TurboJPEG Java API. It can be run with
+`java -cp turbojpeg.jar TJBench`.
+
+8. cjpeg can now be used to generate JPEG files with the RGB colorspace
+(feature ported from jpeg-8d.)
+
+9. The width and height in the `-crop` argument passed to jpegtran can now be
+suffixed with `f` to indicate that, when the upper left corner of the cropping
+region is automatically moved to the nearest iMCU boundary, the bottom right
+corner should be moved by the same amount. In other words, this feature causes
+jpegtran to strictly honor the specified width/height rather than the specified
+bottom right corner (feature ported from jpeg-8d.)
+
+10. JPEG files using the RGB colorspace can now be decompressed into grayscale
+images (feature ported from jpeg-8d.)
+
+11. Fixed a regression caused by 1.2.1[7] whereby the build would fail with
+multiple "Mismatch in operand sizes" errors when attempting to build the x86
+SIMD code with NASM 0.98.
+
+12. The in-memory source/destination managers (`jpeg_mem_src()` and
+`jpeg_mem_dest()`) are now included by default when building libjpeg-turbo with
+libjpeg v6b or v7 emulation, so that programs can take advantage of these
+functions without requiring the use of the backward-incompatible libjpeg v8
+ABI. The "age number" of the libjpeg-turbo library on Un*x systems has been
+incremented by 1 to reflect this. You can disable this feature with a
+configure/CMake switch in order to retain strict API/ABI compatibility with the
+libjpeg v6b or v7 API/ABI (or with previous versions of libjpeg-turbo.) See
+[README.md](README.md) for more details.
+
+13. Added ARMv7s architecture to libjpeg.a and libturbojpeg.a in the official
+libjpeg-turbo binary package for OS X, so that those libraries can be used to
+build applications that leverage the faster CPUs in the iPhone 5 and iPad 4.
+
+
+1.2.1
+=====
+
+### Significant changes relative to 1.2.0:
+
+1. Creating or decoding a JPEG file that uses the RGB colorspace should now
+properly work when the input or output colorspace is one of the libjpeg-turbo
+colorspace extensions.
+
+2. When libjpeg-turbo was built without SIMD support and merged (non-fancy)
+upsampling was used along with an alpha-enabled colorspace during
+decompression, the unused byte of the decompressed pixels was not being set to
+0xFF. This has been fixed. TJUnitTest has also been extended to test for the
+correct behavior of the colorspace extensions when merged upsampling is used.
+
+3. Fixed a bug whereby the libjpeg-turbo SSE2 SIMD code would not preserve the
+upper 64 bits of xmm6 and xmm7 on Win64 platforms, which violated the Win64
+calling conventions.
+
+4. Fixed a regression caused by 1.2.0[6] whereby decompressing corrupt JPEG
+images (specifically, images in which the component count was erroneously set
+to a large value) would cause libjpeg-turbo to segfault.
+
+5. Worked around a severe performance issue with "Bobcat" (AMD Embedded APU)
+processors. The `MASKMOVDQU` instruction, which was used by the libjpeg-turbo
+SSE2 SIMD code, is apparently implemented in microcode on AMD processors, and
+it is painfully slow on Bobcat processors in particular. Eliminating the use
+of this instruction improved performance by an order of magnitude on Bobcat
+processors and by a small amount (typically 5%) on AMD desktop processors.
+
+6. Added SIMD acceleration for performing 4:2:2 upsampling on NEON-capable ARM
+platforms. This speeds up the decompression of 4:2:2 JPEGs by 20-25% on such
+platforms.
+
+7. Fixed a regression caused by 1.2.0[2] whereby, on Linux/x86 platforms
+running the 32-bit SSE2 SIMD code in libjpeg-turbo, decompressing a 4:2:0 or
+4:2:2 JPEG image into a 32-bit (RGBX, BGRX, etc.) buffer without using fancy
+upsampling would produce several incorrect columns of pixels at the right-hand
+side of the output image if each row in the output image was not evenly
+divisible by 16 bytes.
+
+8. Fixed an issue whereby attempting to build the SIMD extensions with Xcode
+4.3 on OS X platforms would cause NASM to return numerous errors of the form
+"'%define' expects a macro identifier".
+
+9. Added flags to the TurboJPEG API that allow the caller to force the use of
+either the fast or the accurate DCT/IDCT algorithms in the underlying codec.
+
+
+1.2.0
+=====
+
+### Significant changes relative to 1.2 beta1:
+
+1. Fixed build issue with YASM on Unix systems (the libjpeg-turbo build system
+was not adding the current directory to the assembler include path, so YASM
+was not able to find jsimdcfg.inc.)
+
+2. Fixed out-of-bounds read in SSE2 SIMD code that occurred when decompressing
+a JPEG image to a bitmap buffer whose size was not a multiple of 16 bytes.
+This was more of an annoyance than an actual bug, since it did not cause any
+actual run-time problems, but the issue showed up when running libjpeg-turbo in
+valgrind. See <http://crbug.com/72399> for more information.
+
+3. Added a compile-time macro (`LIBJPEG_TURBO_VERSION`) that can be used to
+check the version of libjpeg-turbo against which an application was compiled.
+
+4. Added new RGBA/BGRA/ABGR/ARGB colorspace extension constants (libjpeg API)
+and pixel formats (TurboJPEG API), which allow applications to specify that,
+when decompressing to a 4-component RGB buffer, the unused byte should be set
+to 0xFF so that it can be interpreted as an opaque alpha channel.
+
+5. Fixed regression issue whereby DevIL failed to build against libjpeg-turbo
+because libjpeg-turbo's distributed version of jconfig.h contained an `INLINE`
+macro, which conflicted with a similar macro in DevIL. This macro is used only
+internally when building libjpeg-turbo, so it was moved into config.h.
+
+6. libjpeg-turbo will now correctly decompress erroneous CMYK/YCCK JPEGs whose
+K component is assigned a component ID of 1 instead of 4. Although these files
+are in violation of the spec, other JPEG implementations handle them
+correctly.
+
+7. Added ARMv6 and ARMv7 architectures to libjpeg.a and libturbojpeg.a in
+the official libjpeg-turbo binary package for OS X, so that those libraries can
+be used to build both OS X and iOS applications.
+
+
+1.1.90 (1.2 beta1)
+==================
+
+### Significant changes relative to 1.1.1:
+
+1. Added a Java wrapper for the TurboJPEG API. See [java/README](java/README)
+for more details.
+
+2. The TurboJPEG API can now be used to scale down images during
+decompression.
+
+3. Added SIMD routines for RGB-to-grayscale color conversion, which
+significantly improves the performance of grayscale JPEG compression from an
+RGB source image.
+
+4. Improved the performance of the C color conversion routines, which are used
+on platforms for which SIMD acceleration is not available.
+
+5. Added a function to the TurboJPEG API that performs lossless transforms.
+This function is implemented using the same back end as jpegtran, but it
+performs transcoding entirely in memory and allows multiple transforms and/or
+crop operations to be batched together, so the source coefficients only need to
+be read once. This is useful when generating image tiles from a single source
+JPEG.
+
+6. Added tests for the new TurboJPEG scaled decompression and lossless
+transform features to tjbench (the TurboJPEG benchmark, formerly called
+"jpgtest".)
+
+7. Added support for 4:4:0 (transposed 4:2:2) subsampling in TurboJPEG, which
+was necessary in order for it to read 4:2:2 JPEG files that had been losslessly
+transposed or rotated 90 degrees.
+
+8. All legacy VirtualGL code has been re-factored, and this has allowed
+libjpeg-turbo, in its entirety, to be re-licensed under a BSD-style license.
+
+9. libjpeg-turbo can now be built with YASM.
+
+10. Added SIMD acceleration for ARM Linux and iOS platforms that support
+NEON instructions.
+
+11. Refactored the TurboJPEG C API and documented it using Doxygen. The
+TurboJPEG 1.2 API uses pixel formats to define the size and component order of
+the uncompressed source/destination images, and it includes a more efficient
+version of `TJBUFSIZE()` that computes a worst-case JPEG size based on the
+level of chrominance subsampling. The refactored implementation of the
+TurboJPEG API now uses the libjpeg memory source and destination managers,
+which allows the TurboJPEG compressor to grow the JPEG buffer as necessary.
+
+12. Eliminated errors in the output of jpegtran on Windows that occurred when
+the application was invoked using I/O redirection
+(`jpegtran <input.jpg >output.jpg`.)
+
+13. The inclusion of libjpeg v7 and v8 emulation as well as arithmetic coding
+support in libjpeg-turbo v1.1.0 introduced several new error constants in
+jerror.h, and these were mistakenly enabled for all emulation modes, causing
+the error enum in libjpeg-turbo to sometimes have different values than the
+same enum in libjpeg. This represents an ABI incompatibility, and it caused
+problems with rare applications that took specific action based on a particular
+error value. The fix was to include the new error constants conditionally
+based on whether libjpeg v7 or v8 emulation was enabled.
+
+14. Fixed an issue whereby Windows applications that used libjpeg-turbo would
+fail to compile if the Windows system headers were included before jpeglib.h.
+This issue was caused by a conflict in the definition of the INT32 type.
+
+15. Fixed 32-bit supplementary package for amd64 Debian systems, which was
+broken by enhancements to the packaging system in 1.1.
+
+16. When decompressing a JPEG image using an output colorspace of
+`JCS_EXT_RGBX`, `JCS_EXT_BGRX`, `JCS_EXT_XBGR`, or `JCS_EXT_XRGB`,
+libjpeg-turbo will now set the unused byte to 0xFF, which allows applications
+to interpret that byte as an alpha channel (0xFF = opaque).
+
+
+1.1.1
+=====
+
+### Significant changes relative to 1.1.0:
+
+1. Fixed a 1-pixel error in row 0, column 21 of the luminance plane generated
+by `tjEncodeYUV()`.
+
+2. libjpeg-turbo's accelerated Huffman decoder previously ignored unexpected
+markers found in the middle of the JPEG data stream during decompression. It
+will now hand off decoding of a particular block to the unaccelerated Huffman
+decoder if an unexpected marker is found, so that the unaccelerated Huffman
+decoder can generate an appropriate warning.
+
+3. Older versions of MinGW64 prefixed symbol names with underscores by
+default, which differed from the behavior of 64-bit Visual C++. MinGW64 1.0
+has adopted the behavior of 64-bit Visual C++ as the default, so to accommodate
+this, the libjpeg-turbo SIMD function names are no longer prefixed with an
+underscore when building with MinGW64. This means that, when building
+libjpeg-turbo with older versions of MinGW64, you will now have to add
+`-fno-leading-underscore` to the `CFLAGS`.
+
+4. Fixed a regression bug in the NSIS script that caused the Windows installer
+build to fail when using the Visual Studio IDE.
+
+5. Fixed a bug in `jpeg_read_coefficients()` whereby it would not initialize
+`cinfo->image_width` and `cinfo->image_height` if libjpeg v7 or v8 emulation
+was enabled. This specifically caused the jpegoptim program to fail if it was
+linked against a version of libjpeg-turbo that was built with libjpeg v7 or v8
+emulation.
+
+6. Eliminated excessive I/O overhead that occurred when reading BMP files in
+cjpeg.
+
+7. Eliminated errors in the output of cjpeg on Windows that occurred when the
+application was invoked using I/O redirection (`cjpeg <inputfile >output.jpg`.)
+
+
+1.1.0
+=====
+
+### Significant changes relative to 1.1 beta1:
+
+1. The algorithm used by the SIMD quantization function cannot produce correct
+results when the JPEG quality is >= 98 and the fast integer forward DCT is
+used. Thus, the non-SIMD quantization function is now used for those cases,
+and libjpeg-turbo should now produce identical output to libjpeg v6b in all
+cases.
+
+2. Despite the above, the fast integer forward DCT still degrades somewhat for
+JPEG qualities greater than 95, so the TurboJPEG wrapper will now automatically
+use the slow integer forward DCT when generating JPEG images of quality 96 or
+greater. This reduces compression performance by as much as 15% for these
+high-quality images but is necessary to ensure that the images are perceptually
+lossless. It also ensures that the library can avoid the performance pitfall
+created by [1].
+
+3. Ported jpgtest.cxx to pure C to avoid the need for a C++ compiler.
+
+4. Fixed visual artifacts in grayscale JPEG compression caused by a typo in
+the RGB-to-luminance lookup tables.
+
+5. The Windows distribution packages now include the libjpeg run-time programs
+(cjpeg, etc.)
+
+6. All packages now include jpgtest.
+
+7. The TurboJPEG dynamic library now uses versioned symbols.
+
+8. Added two new TurboJPEG API functions, `tjEncodeYUV()` and
+`tjDecompressToYUV()`, to replace the somewhat hackish `TJ_YUV` flag.
+
+
+1.0.90 (1.1 beta1)
+==================
+
+### Significant changes relative to 1.0.1:
+
+1. Added emulation of the libjpeg v7 and v8 APIs and ABIs. See
+[README.md](README.md) for more details. This feature was sponsored by
+CamTrace SAS.
+
+2. Created a new CMake-based build system for the Visual C++ and MinGW builds.
+
+3. Grayscale bitmaps can now be compressed from/decompressed to using the
+TurboJPEG API.
+
+4. jpgtest can now be used to test decompression performance with existing
+JPEG images.
+
+5. If the default install prefix (/opt/libjpeg-turbo) is used, then
+`make install` now creates /opt/libjpeg-turbo/lib32 and
+/opt/libjpeg-turbo/lib64 sym links to duplicate the behavior of the binary
+packages.
+
+6. All symbols in the libjpeg-turbo dynamic library are now versioned, even
+when the library is built with libjpeg v6b emulation.
+
+7. Added arithmetic encoding and decoding support (can be disabled with
+configure or CMake options)
+
+8. Added a `TJ_YUV` flag to the TurboJPEG API, which causes both the compressor
+and decompressor to output planar YUV images.
+
+9. Added an extended version of `tjDecompressHeader()` to the TurboJPEG API,
+which allows the caller to determine the type of subsampling used in a JPEG
+image.
+
+10. Added further protections against invalid Huffman codes.
+
+
+1.0.1
+=====
+
+### Significant changes relative to 1.0.0:
+
+1. The Huffman decoder will now handle erroneous Huffman codes (for instance,
+from a corrupt JPEG image.) Previously, these would cause libjpeg-turbo to
+crash under certain circumstances.
+
+2. Fixed typo in SIMD dispatch routines that was causing 4:2:2 upsampling to
+be used instead of 4:2:0 when decompressing JPEG images using SSE2 code.
+
+3. The configure script will now automatically determine whether the
+`INCOMPLETE_TYPES_BROKEN` macro should be defined.
+
+
+1.0.0
+=====
+
+### Significant changes relative to 0.0.93:
+
+1. 2983700: Further FreeBSD build tweaks (no longer necessary to specify
+`--host` when configuring on a 64-bit system)
+
+2. Created symlinks in the Unix/Linux packages so that the TurboJPEG
+include file can always be found in /opt/libjpeg-turbo/include, the 32-bit
+static libraries can always be found in /opt/libjpeg-turbo/lib32, and the
+64-bit static libraries can always be found in /opt/libjpeg-turbo/lib64.
+
+3. The Unix/Linux distribution packages now include the libjpeg run-time
+programs (cjpeg, etc.) and man pages.
+
+4. Created a 32-bit supplementary package for amd64 Debian systems, which
+contains just the 32-bit libjpeg-turbo libraries.
+
+5. Moved the libraries from */lib32 to */lib in the i386 Debian package.
+
+6. Include distribution package for Cygwin
+
+7. No longer necessary to specify `--without-simd` on non-x86 architectures,
+and unit tests now work on those architectures.
+
+
+0.0.93
+======
+
+### Significant changes since 0.0.91:
+
+1. 2982659: Fixed x86-64 build on FreeBSD systems
+
+2. 2988188: Added support for Windows 64-bit systems
+
+
+0.0.91
+======
+
+### Significant changes relative to 0.0.90:
+
+1. Added documentation to .deb packages
+
+2. 2968313: Fixed data corruption issues when decompressing large JPEG images
+and/or using buffered I/O with the libjpeg-turbo decompressor
+
+
+0.0.90
+======
+
+Initial release
projects / libjpeg-turbo / commitdiff